1. Technical Field of the Invention
The invention relates to optical display devices, and to methods for making the same.
2. Background of the Related Art
Liquid crystal display (LCD) devices are one example of well-known display devices that are useful in a number of applications where light weight, low power and a flat panel display are desired. Typically, these devices comprise a pair of sheet-like, glass substrate elements or “half-cells” overlying one another with liquid crystal material confined between the glass substrates. The substrates are sealed at their periphery with a sealant to form the cell or device. Transparent electrodes are generally applied to the interior surface of the substrates to allow the application of an electric field at various points on the substrates thereby forming addressable pixel areas on the display.
Various types of liquid crystal materials are known in the art and are useful in devices referred to as twisted nematic (TN), super twisted nematic (STN), cholesteric, and ferroelectric display devices.
Other types of display device are electroluminescent displays, such as organic light emitting devices (OLEDs) and polymer light emitting device (PLEDs).
It is desirable to be able to manufacture large area displays of relatively light weight for use in portable devices such as computers, electronic books, personal digital assistants, and the like. Certain organic, polymeric substrates are much lighter than glass while being transparent and are therefore preferred for use over glass in large area, lightweight displays. However, one problem with polymeric substrate displays is the difficulty of properly aligning such substrates, especially if both films are produced using roll-to-roll formation processes. In addition, polymeric substrates often require organic or inorganic coatings with high barrier properties, to prevent ingress of moisture, oxygen, and/or other contaminants into the substrates.